Details:

Creators:
Richardson, E.V. ; Davis, S.R.
Richardson, E.V. ; Davis, S.R. Less -
Corporate Creators:
Ayres Associates ; GKY & Associates
Ayres Associates ; GKY & Associates Less -
Subject/TRT Terms:
[+]
Bridge Design Scour
Publication/ Report Number:
HEC 18
Resource Type:
Tech Report
Geographical Coverage:
United States
OCLC Number:
768771903
Corporate Publisher:
United States. Federal Highway Administration. Office of Technology Applications
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and Structures
Abstract:
This document is the third of HEC 18, i.e., presents the state of knowledge and practice for the design,

evaluation, and inspection of bridges for scour. It contains updated material not included in the second

edition dated April 1993. This document is a revision to HEC 18 dated April 1993 which, in turn, was an

update of HEC 18 dated Feburary 1991 and of the publication, "Interim Procedures for Evaluating Scour

at Bridges," issued in September 1988 as part of the FHWA Technical Advisory T 5140.20, "Scour at

Bridges." T 5140.20 has since been superseded by T 5410.23, "Evaluating Scour at Bridges" dated

October 28,1991. This document contains revisions obtained from further scour-related developments

and use of the 1993 edition of HEC 18 by the highway community.

The principal change from the 1993 edition of HEC 18 is the use of metric (SI) units of measurement.

Additional changes are: a discussion of backwater effects on contraction of scour and the use of the

water surface or the energy grade line as the reference line for measuring contraction scour depths,

addition of a coefficient to the pier scour equation to account for the armoring effect of large particle sizes

in the bed material, and addition of an equation to compute the coefficient applied to the pier scour

equation when there is an angle of attack. Figures have been added to clarify computation of pier scour

for exposed footings, pile caps placed in the flow, multiple columns skewed to the flow, and a scour

resulting from pressure flow. This document includes a method to compute scour depths for pressure flow

when a bridge deck is submerged. A method to compute H for constricted tidal waterways is given

along with the procedure used by Maryland SHD to evaluate scour for bridges over tidal waterways. A

discussion of computer models to determine the value of the hydraulic variables for scour analysis of

bridges over tidal waterways has been added and information on scour detection equipment has been

updated based on recent research. Finally, minor errors in the text and figures have been corrected.


Format:
PDF
Funding:
DTFH61-93-C-00101
Collection(s):
Federal Highway Administration
Main Document Checksum:
[+]
urn:sha256:689a24d2ad4fd39dec7a4bf3adb29477d651fa2013ccaec3305dc0143f4357f3
Download URL:
https://rosap.ntl.bts.gov/view/dot/1024/dot_1024_DS1.pdf
File Type:

Supporting Files

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